will I pay the higher rate stamp duty?

[AP123]

I separated from my wife almost 5 years ago, however I have remained on the mortgage of the matrimonial home due to the fact that my wife doesn't not have the income to take on the mortgage in her own name. She does however pay the mortgage herself from the maintenance that I pay her. I will not take any equity from the house if it is sold, and should she be in a position to take on the mortgage in the future, will happily transfer ownership to her.
Since our separation I have lived in rented accommodation, however I would now like to purchase a home with my new partner.
In this circumstance would I be liable for the higher rate of stamp duty?
I would technically own two homes, however my 'main' residence would change from a rented house to an owned one.
Would the situation change if we were to divorce? In this case it is still likely that I would still have to remain on the mortgage for a number of years.

[maths]

It is unclear whether you have a beneficial interest in the former matrimonial home although I would assume that you do unless you transferred it to your wife on separation?

Assuming you have such an interest then the 3% SDLT charge will apply on your new proposed joint purchase.

Divorce wouldn't help.

[SDLT Geek]

There are some changes in the Autumn Budget today to the 3% stamp duty surcharge rules in this area that help people in this kind of position. But they do depend on a property adjustment order having been made.